Water heater



FIG. 1 is a perspective view of a water heater showing my new design;

FIG. 2 is a side elevational view thereof;

FIG. 3 is a top elevational view thereof;

FIG. 4 is an end elevational view thereof;

FIG. 5 is a side elevational view of the opposite side to that in FIG. 2; and,

FIG. 6 is a bottom view thereof.

The opposite end view is identical to FIG. 4. 

The ornamental design for a water heater, as shown and described. 